在BiDirectional中将NetworkX图边转换为无向边

Question

我使用NetworkX来做以下工作:我有一个有向图g，我想把它转换成一个无向图h，这样h的节点和h的边相同，当e在g中是双向的。例如，我想转换：

import networkx as nx
g = nx.DiGraph([("A", "B"), ("B", "A"), ("A", "C"), ("C", "A"), ("B", "C"), ("C", "B"), ("A", "D"), ("C", "D"), ("B", "E"), ("C", "E")])

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转到

h = nx.Graph([("A", "B"), ("A", "C"), ("B", "C")])
h.add_nodes_from(["D", "E"])

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我应该用f(g) = h写什么NetworkX？我认为这是一些图形视图和过滤器的组合，但我对NetworkX并不熟悉，所以我不确定到底是什么。

Answer 1

您可以通过遍历有向图的边来实现这一点，并检查反向边是否与条件if edge[::-1] in g.edges():一起存在。如果反向边存在，只需将其添加到图中即可。见下面的代码：

import networkx as nx
import matplotlib.pyplot as plt

#Creating directed graph
g = nx.DiGraph([("A", "B"), ("B", "A"), ("A", "C"), ("C", "A"), ("B", "C"), ("C", "B"), ("A", "D"), ("C", "D"), ("B", "E"), ("C", "E")])

#Creating undirected graph
h=nx.Graph()
h.add_nodes_from(g)

for edge in g.edges():  
  if edge[::-1] in g.edges(): #check if reverse edge exist in graph
    h.add_edge(edge[0],edge[1])

#plot both graphs
fig=plt.figure(figsize=(15,6))
plt.subplot(121)
plt.title('Directed graph')
pos1=nx.circular_layout(g)
nx.draw(g,pos=pos1,with_labels=True, node_color='tab:orange')

plt.subplot(122)
plt.title('Undirected graph')
pos2=nx.circular_layout(h)
nx.draw(h,pos=pos2,with_labels=True, node_color='tab:green')

输出结果是：

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